This invention relates to deburring tools, and is particularly concerned with the construction of a deburring tool which is capable of deburring or chamfering the edge of elliptical or out-of-round holes.
It is desirable in the manufacturing industry to have smooth surfaces even after holes are drilled into those surfaces to properly fit parts into the holes or other considerations. The surfaces are generally made smooth by deburring tools. As drilling techniques improved in the machine tool industry, holes were angulated and presented an elliptical or otherwise out-of-round edge profile at the surface. Typically, such out-of-round edge profiles are created by drilling holes through curved or cylindrical surfaces or drilling holes into flat or curved surfaces at an angle not perpendicular to the surface of the workpiece.
The present invention is designed specifically for deburring the surface of these curved, elliptical, or otherwise out-of-round hole edge profiles. The present invention is simple to operate and makes the tool easy to use by unskilled operators. It is only necessary to place the conical tip of the tool in the hole to be deburred and to rotate the tool in a spindle perpendicular to the work surface. When force is applied, the shank of the tool moves towards the workpiece exposing a spring loaded blade that swiftly and smoothly removes the burrs from the outer edge of the hole.
The present invention also has the advantage of being used with any rotating spindle, such as low speed portable hand drills, drill presses, or automatic equipment. Only light contact pressure is necessary to produce the desired cutting action.
The present invention further provides the advantage of adjustment to adapt the tool for use with a wide range of materials. By merely turning a screw, the spring tension on the cutting blade may be either increased or decreased. A light spring tension is used with softer materials while increased tensions are more appropriate for use with harder materials.
Chamfer depth is controlled by the amount of time between the application by the operator of the cutting edge of the blade into engagement with the hole edge and the release of the tool blade from the edge, normally called the dwell time of the tool. Typically the optimal dwell time will be determined after suitable testing operations. Generally the chamfer depth is directly proportional to dwell time up to the point of the operation where the tool will effectively cease to cut.
Further advantages of the present invention are that it is self-piloting and allows the lateral operating range of each tool to vary from the blade tip thickness to the maximum blade width.
A further advantage is that blade replacement in the present invention is extremely simple and involves only the removal of a set screw from the side of the tool. Further, blade life is extended with the present invention in that the blade never encounters the full brunt of the contact force in positioning the tool on the workpiece, but instead encounters only cutting forces, with the shank portion absorbing contact forces.
Further objects, advantages, and features of the invention will become apparent from the following description taken in conjunction with the accompanying drawings.